Actually living in Asia i always see this brand in some small kite school and after discussion with different guys it seems that core is present in those school / shops as they can't meet quantity requirements from the big brands such as North / Naish / Slingshot / Fone etc...
Also 90% of kiter i saw with those kites were beginner, do you know any reason about that ?
Seems the kite are well build but personally i found their design absolutely terrible, but this is a personal preference.
I have a 2014 XR3 9 and 15 (+ Edge 19) the kite with bar and lines is wery well built, I have not seen a kite with better details. I have only used the Core 15, but it flies so nice with the best feeling trough turns that I ever felt on a big kite, I realy like it. I was in El Medano in januar, and there was just 2 others using Core kites there, but they were the best of all the kiters there. no brand affiliation.
I own 3 Core (7, 11 and 15) and they are excellent, well built, no issues in 4 years (my 11). I was the first in my home spot to but a Core and now there are more than 10 Cores in the waters every week end. The LW series is IMO one of the best product for light wind. Now there's the new bar that works like a standard 4 lines "Y" but flags on a single line if you hit the QR, I think it's a real innovation. About the fact they should be for beginners, maybe it's a pure coincidence in your spot The only cons is they are quite expensive but the quality is really top level. No affiliation anyway!